Axial flux motors are a separate category of electric motor that are distinguished from other more conventional electric motors by the direction in which the magnetic flux paths are oriented. In conventional electric motors, the magnetic flux is directed radially through an air gap between the rotor and the stator. There is a small gap between the outer surface of the rotor and the inner diameter of the stator, so these motors are sometimes referred to as radial gap or radial flux machines. In axial flux motors, the magnetic flux is directed in axial direction, i.e., a direction that is parallel to the rotational axis of the motor, and through a small gap between the rotor and the stator. As a consequence, axial flux motors are also sometimes referred to as axial gap motors.
In its most simple form, the axial flux motor has two components: a rotor and a stator. Typically, the rotor is fitted with an array of permanent magnets arranged in an alternating pole configuration and the stator contains an array of wire coils. Electric currents provided to the array of coils within the stator result in a magnetic flux that attracts and repels the different magnets in the rotor, thereby causing it to rotate with respect to the stator and about a rotational axis.
Axial flux motors typically represent a more efficient design than radial flux motors in that they are characterized by a higher torque or power to mass ratio. And they are particularly good for applications in which quick changes in motor speed are desired.